Massey Ferguson 13.X.2D – TRANS1: Brake System Pressure Signal Issue Dyna VT

The transmission controller is receiving an incorrect, erratic, or out-of-range electrical signal from the braking pressure sensor (X135). The system cannot verify the actual hydraulic pressure in the brake circuit, which can affect transmission behavior and safety interlocks.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 6600 Series (6614, 6615, 6616)
• 6700 Series (6712 S, 6715 S, 6716)
• 7600 Series (7615 through 7624)
• 7700 Series (7714 through 7726)
• 8600 Series (8660, 8670, 8680, 8690)
• 8700 Series (8727 through 8740)

1. 1

   Visually inspect the X135 braking pressure sensor electrical connector for water ingress, corrosion, or pushed-out pins.

2. 2

   Perform a wiring continuity test between the X135 sensor and the TRANS1 module to check for an open circuit, short to ground, or short to +12V.

3. 3

   Conduct a hydraulic pressure test using a mechanical gauge at the brake system test port to verify the system builds and drops pressure correctly. If mechanical pressure is abnormal, the issue lies with the hydraulic pump or brake valve, not the sensor.

1. 1

   Park the tractor on a level surface, engage the park lock, lower all implements, and turn off the engine.

2. 2

   Pump the brake pedals several times to safely relieve any residual hydraulic accumulator pressure in the brake circuit.

3. 3

   Locate the X135 brake pressure sensor.

   Clean the area around the sensor to prevent dirt from entering the hydraulic system.

4. 4

   Disconnect the electrical harness from the sensor.

5. 5

   Unscrew and remove the faulty pressure sensor.

   Have a rag ready to catch any minor fluid drips.

6. 6

   Install the new OEM pressure sensor and tighten it to the torque specification outlined in your specific model's service manual.

7. 7

   Reconnect the electrical connector, ensuring it clicks securely into place.

8. 8

   Start the tractor and test the brake pedals.

   Check the sensor fitting for any hydraulic leaks.

9. 9

   Use the tractor's onboard diagnostic screen or a dealer service tool to clear the 13.X.2D fault code.